Its Scott's standard postage stamp ... 1971-

Scott's standard postage stamp catalog, 1972: t.p. (Scott Publishing Co.); 1939: t.p. (Scott Publications, Inc.)

Mellone, M. Mellone's Specialized cachet catalog of first day covers of the 1950's, 1983: t.p. (Scott)

PTLA, 1982 (Scott Publishing Company; New York, N.Y.)